Fire extinguishing bomb



Aug. 31, 1937; GM mz 2,091,589- FIRE EXTINGUISHING BOMB 7 Filed May 4. 1935 5 F i I F a g n 4 Patented Aug. 31, 1937 UNITED- STATES PATENT QFFECE Application May 4, 1935, Serial No. 19,882 In Italy December 12, 1934 4 Claims.

Bombs or grenades have long been used for extinguishing a fire, which bombs, when thrown or deposited in proximity to a fire, break and cause to be spread over the fire solid or liquid 5 substances which develop gases and which quench the fire by absorption of heat and by displacement of the surrounding air. The fact however that the bombs are to be thrown onto the fire means that the bombs can be used only for extinguishing fires which have fully developed. While said bombs are satisfactory for extinguishing fires once they have developed, these bombs are totally incapable of automaticallypreventing this development and propagation of fires from their beginning. At the same time it is impracticable for the bombs to surpass certain limited proportions of weight and volume, due to the necessity of their being easily handled.

The object of the present invention is to produce an automatically-firnctioning extinguishing bomb which is disposed in fixed manner in the premises where a fire is to be avoided, its operation being due to the outburst of an explosive central charge. The bomb is provided with a control device automatically causing the explosion as soon as the temperature of the surrounding room, where the bombs are deposited, reaches limits constituting a fire hazard or indicating that a fire has already occurred.

Such an automatic control device comprises a heat-sensitive means, acting independently of the will of the operator, so that at its very inception, the propagation of a fire may be prevented. Said heat-sensitive means may take various forms, provided only that its reaction on increase of temperature brings into play the elements causing the operation ofthe bomb. Preferably a substance which is fusible at a predetermined temperature is used at the heatsensitive means, but this does not exclude the use of a non-fusible material which, for instance, may be highly expansible upon increase ,of temperature so that at a predetermined temperature the control device will be actuated, causing the operation of the bomb.

The invention comprises a bomb which explodes at the point where it is fixed or suspended such as walls, ceilings of rooms or any localities whatsoever, the exploding bomb spreading the extinguishing material all around.

These and other features of the invention will be best understood and appreciated from the following description of a preferred embodiment as illustrated in the accompanying drawing, in

which:

Fig. 1 shows in axial section an extinguishing bomb of the type which is fixedly secured to the walls or ceiling of a locality.

Fig. 2 shows a bomb similar to that of Fig. 1, with certain constructive variations. 5

Fig. 3 shows how the heat-sensitive control device may be brought into operation at will.

Fig. 1 shows in axial section a fixed extinguishing bomb particularly adapted to be arranged in localitieshaving a low ceiling. The 10 bomb is provided with a screw cap, of the Edison type for instance, extending into a tube-like casing 24 of a resistant material remaining fixed to the cap even after the explosion, at the lower end of which casing a cartridge 25 containing the 15 explosive charge is centrally arranged in the envelope 26 of the bomb, of a frangible material. The bomb is made fast, by means such as the fixing device 21, to the upper section of the casing 24 immediately under its widened part 28 form- 2 ing a prolongation of the cap 23. This part 26 is shown as provided interiorly and at its upper part with a supporting fiange 29 sustaining the heat-sensitive control or fusible disc 30; and it is also shown ashaving mounted on its exterior 25 the disc-shaped heat collector 3!. This heatcollector 3i may also be fast with the flange 29 above-mentioned. The heat-sensitive control disc 30, calibrated for a determined temperature, fused by the heat collected and transmitted by 30 collector 3|, ceases retaining the pointedstriker 32 which, acted on by spring 33, bearing against the lower fiange 34 of the widened section 28, strikes the fulminating capsule 35 so that the detonator 36 is ignited, causing the explosion 35 of the cartridge 25. The abrupt pressure thus generated smashes'the bomb and homogeneously scatters the extinguishing substance contained in the bomb about, quenching the fire.

In certain special applications of the bomb, it 40 is advisable to provide the pointed striker 32, in its upper part near the heat-sensitive control disc 30, with a hole into which is slipped, with a free play, a small safety and controlling pivot 31.

Fig. 2 shows in an axial section a, similar bomb 45 provided with a hook suspension comprising the hood 38 with hook 39, the hood merging into a casing 40 supporting, by means such as flanges 4|, the envelope 42 of the bomb. In its upper end said casing 40, acting as a bomb-holder, is 50 provided with a flange 43 shaped in any suitable way solid with and in intimate contact with the heat collector 44, connected to the heat-sensitive control 45 in suitable manner so that the fusion temperature may be easily and safely trans- 55 mitted. The heat-sensitive control 45, by reacting at the temperature for which it has been calibrated, releases the rod 46 which at its lower end sustains the hammer mass M, which under the'action of spring 48, hits the striker t9, driving the latter in turn into the detonator 50, thereby; causing the deflagration of the explosive charge 5| of cartridge which is centrally arranged in the envelope to of the extinguishing bomb, which is then smashed to minute pieces, thereby scattering the extinguishing substance all around and generating the asphyxiating atmosphere for quenching the fire.

The illustrated embodiment of the extinguish,- ing bomb may for certain particular applications (ships holds and cabins, refrigerating chambers, silos and the like) be provided with electric resistances 53 surrounding or included in the heatsensitive control 5 3, as illustrated in Fig. 3. These electric resistances make it possible to connect the bombs in series or in parallel, or as a combination of the two systems, in an electric network in order that the ships oflicers may explode the bombs at will, singly or in groups, to create a fire-extinguishing atmosphere in the localities surrounding the seat of fire, to prevent the propagation of the latter.

When the atmosphere of the region where the bomb is placed reaches a point at which the heatsensitive control disc fuses, the latter releases the striker to fall against the detonating capsule; the explosive charge, by bursting, smashing to pieces the envelope of the bomb and the extinguishing substance thus being scattered all around in the room where the bomb is located.

The operation of the bomb is as follows: The bomb is either suspended fromthe ceiling by hook 39 or screwed ina socket by means of the screw threaded cap 23. If in the enclosure, or room, where the bomb is suspended, a temperature is developed higher than that tolerated by the heat sensitive control 30, the fusible disc 30 is'easily melted, due to the transmission of heat from the heat collector. The pointed striker 32 is thus released, striking the fulminating capsule 35 and igniting the detonator 36. When the detonator 36 is ignited, the cartridge 25 explodes, so that the envelope 26 of the bomb is smashed to pieces and the extinguishing substance is spread violently in all directions to quench the fire. By means of a charge of pulverized matter projected in this manner, a cloud like suspension with a whirling motion is generated in the region of the fire, penetrating into the smallest cavities. Thus all the fire is quenched.

It is obvious that once the broad features of 'my invention are disclosed numerous modifications will readily occur to those skilled in the art, without departing from the scope of my invention. Accordingly, I intend that my invention be limited solely by the scope of the appended claims. 7

Having now particularly described and ascertained the nature of my said invention and in what manner the same is-to 'be performed, I declare that what I claim is:

1. A fire-extinguishing equipment, comprising in combination, a bomb having a detonator, an explosive charge and fire-extinguishing material therein, a tubular member extending radially through said bomb to the center thereof and protruding from the exterior of said bomb, the said head of said detonator being seated in exposed manner in the bore of said tubular memher, a base formed on the exterior end of said accuses tubular member, a heat collector thermally secured to said tubular member near its base, and extending beyond the shadow of said bomb, a fusible element in said tubular member near said heat collector and adapted to be fused by heat transmitted thereto from said heat collector, and means adapted. tobe actuated upon fusion of said fusible member for striking said detonator and exploding the bomb.

2. A fire-extinguishing equipment, comprising a bomb, having a casing, a tubular member extending through said bomb to approximately the center thereof, and terminating in an enlarged portion, the casing, tubular member containing a fire-extinguishing material, an explosive charge disposed in the enlarged portion of said tubular member, a detonator associated with said explosive charge and disposed in the bore of said tubular member, said tubular member extending beyond the exterior of said casing, a base formed on the end of said tubular member for securing said bomb to a support, a heat collector formed on said tubular member near said base and extending beyond the shadow of said casing, a fusible element disposed in said tubular member, adjacent said heat collector and adapted to be raised to its fusion point by heat collected by said collector and transmitted to said fusible element, a pointed striker in said tubular member and having a head normally retained by said fusible element, and a spring coiled around said pointed striker and adapted to drive the same, when the latter is released by fusion of the fusible element, against the detonator, puncturing the same and exploding the bomb.

3. A fire-extinguishing equipment, comprising a bomb, having a casing, a tubular member extending through said bomb to approximately the center thereof, and terminating in an enlarged portion, the casing with the exception of the tubular member containing a fire-extinguishing material, an explosive charge disposed in the enlarged portion of said tubular member, a detonator associated with said explosive charge and disposed in the bore of said tubular member, said tubular member extending beyond the exterior of said casing, a base formed on the end of said tubular member for securing said bomb to a support, a heat collector formed on said tubular member near said base and extending beyond the shadow of said casing, a fusible element disposed in said tubular member, adjacent said heat collector and adapted to be raised to its fusion point by heat collected by said collector and transmitted to said fusible element, a puncturing pin disposed in said tubular member immediately above and in contact with said detonator, and a hammer mass suspended in said tubular member and normally supported by said fusible member, fusion of the fusible member by heat transmitted thereto from the heat collector resulting in falling of the hammer mass against the puncturing pin, whereby the detonator is struck off and the bomb explodes.

4. A fire-extinguishing equipment, comprising a bomb, having a casing, a tubular member extending through said bomb to approximately the center thereof, and terminating in an enlarged portion, the casing with the exception of the tubular member containing a fire-extinguishing material, an explosive charge disposed in the enlarged portion of said tubular member, a detonator associated with said explosive charge and disposed in the bore of said tubular member, said with the exception of the l 9,091,589 extending beyond the exterior.

tubular member of said casing, a base formed on the end 01 said tubular member for securing said bomb to a sup-' port. a heat collector formed on said tubular member near said base and extending beyond the shadow of said casing, a fusible element disposed in said tubular member, adjacent said heat collector and adapted to be raised to its fusion point by heat collected by said collector and transmitted to said fusible element. a puncturing pin disposed in said tubular member immediately above and in contact with said detonator, a hammer mass suspended in said tubular member and normally supported by said fusible element, and a coiled spring tending to drive said hammer mass downwardly, fusion or the fusible element by heat transmitted thereto from the heat collector resulting in release of the hammer mass, whereupon the latter is driven downwardly by the combined action of gravity and the said spring, against said puncturing pin, striking oh the -detonator and exploding the bomb.

GINO FINZI. 

